demonstrate asynchronous execution (-j (jobs) limits not supported)
limit number of jobs using semaphores
commit examples of workflow and its output in png
integrate asynchronous execution in core.clj
refactoring
remove binary files
add -j as non-flag-short
set-jobs-semaphore got mistakenly lost in merge
error handling
Vineyard: fix compile error
Merge remote-tracking branch 'origin/guillaume-async' into vineyard-empty-dir-async